This invention relates to a memory having a bit block transfer function.
In computer graphics, hardware designed exclusively for image data processing enables a higher speed of image data processing than the speed of image data processing executed by a combination of software and a processor unit. Recently, there has been a trend toward the use of hardware instead of a software technique in image data processing.
Frame memories having a bit block transfer function are often used in image data processing systems. According to an example of image data processing which uses a bit block transfer function, first image data is read out from a certain rectangular region of a frame memory, and given logic operation is executed between the first image data and externally-fed data to convert the first image data into second image data before the second image data is written into the same or another rectangular region of the frame memory.
As will be explained later, the speed of bit block transfer and related data processing in a prior art memory tends to be low.